Reduced pressure treatment system having blockage clearing and dual-zone pressure protection capabilities

Information

  • Patent Grant
  • 8328776
  • Patent Number
    8,328,776
  • Date Filed
    Monday, June 28, 2010
    14 years ago
  • Date Issued
    Tuesday, December 11, 2012
    11 years ago
Abstract
A method of treating a tissue site is provided. The method includes applying a reduced pressure to a tissue site with a reduced pressure source. A source pressure is monitored at the reduced pressure source, and a differential pressure is determined between the source pressure and the desired tissue site pressure. If a blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a first maximum differential pressure. If no blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a second maximum differential pressure.
Description
BACKGROUND OF THE INVENTION

1. Field of the Invention


The present invention relates generally to tissue treatment devices and in particular to a reduced pressure treatment system having blockage clearing and dual-zone pressure protection capabilities.


2. Description of Related Art


Clinical studies and practice have shown that providing a reduced pressure in proximity to a tissue site augments and accelerates the growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but one particular application of reduced pressure has involved treating wounds. This treatment (frequently referred to in the medical community as “negative pressure wound therapy,” “reduced pressure therapy,” or “vacuum therapy”) provides a number of benefits, including migration of epithelial and subcutaneous tissues, improved blood flow, and micro-deformation of tissue at the wound site. Together these benefits result in increased development of granulation tissue and faster healing times.


While reduced pressure can greatly benefit wound care and other instances where increased tissue growth is indicated, the amount of reduced pressure applied to a tissue site must be controlled to prevent damage to tissue and the possibility of excessive bleeding. It is a common occurrence for blockages to develop in systems that provide reduced pressure therapy. The usual method for addressing these blockages involves the application of additional negative pressure. This additional negative pressure can present a hazard to the safe use of these devices. A need therefore exists for a reduced pressure treatment system and method that is capable of balancing the application of reduced pressure to encourage tissue growth, yet prevent over application of reduced pressure that may cause damage to the tissue.


BRIEF SUMMARY OF THE INVENTION

The problems presented in controlling the pressures applied by a tissue treatment system are solved by the systems and methods of the present invention. In one embodiment, a reduced pressure treatment system is provided that includes a reduced pressure source fluidly connected to a tissue site. A sensing device is provided in communication with the reduced pressure source to measure a source pressure at the reduced pressure source. A processing unit is in communication with the sensing device and is configured to determine a differential pressure between the source pressure and a desired tissue site pressure. The processing unit is further in communication with the reduced pressure source to regulate the source pressure applied by the reduced pressure source. The pressure is regulated such that the differential pressure does not exceed (a) a first maximum differential pressure if a blockage is present between the reduced pressure source and the tissue site and (b) a second maximum differential pressure if no blockage is present between the reduced pressure source and the tissue site.


In accordance with another embodiment of the present invention, a method of treating a tissue site is provided. The method includes applying a reduced pressure to a tissue site with a reduced pressure source. A source pressure is monitored at the reduced pressure source, and a differential pressure between the source pressure and the desired tissue site pressure is determined. If a blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a first maximum differential pressure. If no blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a second maximum differential pressure.


In still another embodiment of the present invention, a reduced pressure treatment system includes a means for applying reduced pressure to a tissue site and a means for monitoring a source pressure at the means for applying reduced pressure. The system further includes a means for determining a differential pressure between the source pressure and the desired tissue site pressure. A means is provided for limiting the differential pressure to a first maximum differential pressure if a blockage is present between the tissue site and the means for applying reduced pressure. The system further includes a means for limiting the differential pressure to a second maximum differential pressure that is higher than the first maximum differential pressure if no blockage is present between the tissue site and the means for applying reduced pressure.


Other objects, features, and advantages of the present invention will become apparent with reference to the drawings and detailed description that follow.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 illustrates a schematic of a reduced pressure treatment system having a reduced pressure therapy unit according to an embodiment of the present invention;



FIG. 2 depicts a block diagram of the reduced pressure therapy unit of FIG. 1; and



FIG. 3 illustrates a flow chart of an exemplary method of treating a tissue site according to an embodiment of the present invention.





DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.


The term “reduced pressure” as used herein generally refers to a pressure less than the ambient pressure at a tissue site that is being subjected to treatment. In most cases, this reduced pressure will be less than the atmospheric pressure at which the patient is located. Although the terms “vacuum” and “negative pressure” may be used to describe the pressure applied to the tissue site, the actual pressure applied to the tissue site may be significantly less than the pressure normally associated with a complete vacuum. Consistent with this nomenclature, an increase in reduced pressure or vacuum pressure refers to a relative reduction of absolute pressure, while a decrease in reduced pressure or vacuum pressure refers to a relative increase of absolute pressure.


The term “tissue site” as used herein refers to a wound or defect located on or within any tissue, including but not limited to, bone tissue, adipose tissue, muscle tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. The term “tissue site” may further refer to areas of any tissue that are not necessarily wounded or defective, but are instead areas in which it is desired to add or promote the growth of additional tissue. For example, reduced pressure tissue treatment may be used in certain tissue areas to grow additional tissue that may be harvested and transplanted to another tissue location.


Referring to FIG. 1, a reduced pressure treatment system 100 according to an embodiment of the present invention is provided to deliver a reduced pressure to a tissue site 102 of a patient. The reduced pressure treatment system 100 includes a reduced pressure source 104 fluidly connected by a conduit 108 to a canister 112. The canister 112 is fluidly connected by a conduit 116 to a manifold adapter 120, which is in contact and fluid communication with a distribution manifold 124. Distribution manifold 124 is placed in contact with the tissue site 102. A drape 128 is positioned over the distribution manifold 124 and is preferably sealed to tissue surrounding the perimeter of the tissue site 102. The manifold adapter 120 preferably protrudes through the drape 128, and the drape 128 is sealed to the manifold adapter 120. The drape 128 may be made from an impermeable or semi-permeable material to assist in maintaining reduced pressure at the tissue site 102.


The distribution manifold 124 is primarily responsible for distributing reduced pressure to the tissue site 102, channeling exudates and other fluids away from the tissue site 102, inducing micro-deformation at the tissue site 102, and supporting the drape 128 to create a space in which reduced pressure is maintained. In practice, the distribution manifold 124 is typically an open-cell foam such as a reticulated polyurethane or polyvinyl alcohol foam. The open-cell foam is sized to fit the tissue site 102, placed into contact with the tissue 102, and then periodically replaced with smaller pieces of foam as tissue begins to grow and the tissue site 102 becomes smaller. Frequent replacement of the open-cell foam is necessary to minimize the in-growth of tissue into the cells of the foam. Despite the common use of open-cell foams, many alternative materials may be used as replaceable distribution manifolds, including gauze and any other materials capable of providing distribution characteristics. Similarly, non-replaceable, biocompatible materials may be used as a distribution manifold and then allowed to remain in place at the tissue site 102. In most cases, these biocompatible materials will serve as scaffolds for new tissue growth, and if bioresorbable, will be absorbed by the patient's body during or following treatment.


The reduced pressure treatment system 100 further includes a first sensing device 132 in communication with the tissue site 102 to measure a pressure at the tissue site 102. A second sensing device 136 is in communication with the reduced pressure source 104 to measure a source pressure at the reduced pressure source 104. The first and second sensing devices 132, 136 may be pressure sensors or any other type of sensors capable of determining a pressure of a fluid (i.e. a liquid or a gas). The first and second sensing devices 132, 136 may include processing units (not illustrated) to assist in collecting, interpreting, conditioning, or transmitting data. The physical connection between the sensing devices 132, 136 and the fluid components of the reduced pressure treatment system 100 may vary depending on the type of sensing device 132, 136 that is used. Similarly, the physical location at which each sensing device 132, 136 is connected to the fluid components of the reduced pressure treatment system 100 may vary as long as the desired pressure, or an approximation thereof, is being determined. The first sensing device 132 is illustrated in FIG. 1 as being physically connected to the conduit 116 near the manifold adapter 120. Although this is one possible configuration, in another embodiment, the first sensing device 132 is a pressure sensor and is fluidly connected through a measurement lumen of conduit 116 to the space beneath drape 128. By providing multiple lumens in conduit 116 (at least one for delivery of reduced pressure and at least one for measurement of the tissue site pressure), the first sensing device 132 may be located remotely from the tissue site 102. The first sensing device 132 may be placed in a variety of locations as long as the tissue site pressure determined by the first sensing device 132 substantially approximates the pressure to which the tissue site 102 is exposed.


With respect to the second sensing device 136, the second sensing device 136 may be connected to the conduit 108 (illustrated in FIG. 1) or to the canister 112 to determine the source pressure, which corresponds to the reduced pressure that is output by the reduced pressure source 104. Alternatively, the second sensing device 136 may be placed in communication with an output port of the reduced pressure source 104 to directly measure the amount of vacuum pressure being produced by the reduced pressure source 104.


Referring still to FIG. 1, but also to FIG. 2, the reduced pressure source 104 and the canister 112 may be contained within or mounted on a reduced pressure therapy unit 140. The therapy unit 140 may also contain first and second sensing devices 132, 136, as well as a processing unit 210 that executes software 214. The processing unit 210 may be configured with one or more processors that are the same or different types. For example, the processing unit 210 may include one or more processors, logic, analog components, or any other electronics that enable signals including information, such as fluid pressure at a tissue site, to be received.


The processing unit 210 may further be in communication with (i) a memory 218 for storing data and software code, (ii) an input/output (I/O) unit 222 for communicating with other devices and systems, such as a valves or sensing devices, wirelessly, via a wire, or via a memory input device (not shown), (iii) a storage unit 226 that may store one or more data repositories 228a-228n (collectively 228), such as a database having one or more files, (iv) an electronic display 232 that may or may not be touch-sensitive, and (v) an alarm 236 that is capable of signaling a user of the reduced pressure therapy unit 140 using audio, visual, or other signals. The software 214 may be configured to interface with each of the other devices (e.g., electronic display 232) to allow management and observation of the reduced pressure treatment.


The processing unit 210 is in communication with the first and second sensing devices 132, 136 to control the application of reduced pressure by the reduced pressure source 104. In operation, a target pressure is prescribed (preferably by a doctor or other approved medical personnel) for delivery to the tissue site 102. The target pressure is the “desired” reduced pressure to which the tissue site 102 should be exposed. The desired tissue site pressure will vary from tissue site to tissue site, but will generally be chosen based on the type of tissue making up the tissue site, the type of injury or wound (if any), the medical condition of the patient, and the preference of the attending physician. After selecting the desired tissue site pressure, the reduced pressure source 104 is operated to achieve the desired tissue site pressure at the wound. In many cases, the reduced pressure source 104 will need to be operated at a higher reduced pressure (i.e. lower absolute pressure) than that of the desired tissue site pressure due to pressure losses between the reduced pressure source 104 and the tissue site 102. Moreover, the head pressure of exudates and other fluids within the conduits may result in a reduction of vacuum pressure at the tissue site 102. In FIG. 1, the height, H, of the canister 112 above the tissue site 102 will determine the amount of head pressure imposed on the tissue site 102 by fluid in the conduit 116. For exudates and fluids with a density similar to water, the head pressure imposed by one foot of fluid is almost 25 mm Hg. Some fluids withdrawn from the tissue site may be heavier or more viscous than water, and therefore have a more pronounced effect on pressure losses at the tissue site 102.


As an example of the potential losses caused by the weight of fluid in the conduits, a prescribed target pressure for a particular tissue site may be −125 mm Hg. If the canister 112 is positioned four feet above the tissue site, and if the conduit 116 between the canister 112 and tissue site 102 is completely full of fluid, the head pressure imposed by that fluid could be almost 100 mm Hg. This particular example may be very common if a tissue site is located on a lower extremity of a patient such as a foot and the canister 112 is mounted near or above the patient's head (e.g., on an IV pole when the patient is in a wheelchair). If the head pressure of fluid in the conduit 116 is approximately 100 mm Hg, a source pressure of approximately −225 mm Hg would need to be applied to result in a tissue site pressure of −125 mm Hg.


Another factor that can reduce the tissue site pressure (relative to the source pressure) is a conduit blockage between the tissue site 102 and the reduced pressure source 104. A pressure differential between the pressure supplied by the reduced pressure source 104 (i.e. the source pressure) and the desired tissue site pressure 102 is important to monitor because of the possibility that the pressure differential is at least partially caused by a blockage. If a blockage exists, it is obviously important to clear the blockage as soon as possible. Blockages prevent application of prescribed target pressures, which result in treatment delays and slower healing. On the other hand, attempting to clear a blockage by applying additional pressure to the conduits can be dangerous if the differential pressure across the blockage becomes too great. When a blockage clears in the presence of a high reduced pressure (relative to the tissue site), this high reduced pressure is almost instantaneously communicated to the tissue site. The rapid onset of additional reduced pressure at the tissue site may cause damage to tissues and initiate excessive bleeding.


The reduced pressure treatment system 100 described herein provides protection against harm to the tissue site 102 caused by high negative pressures while providing the ability to overcome high head pressures under normal (no blockage) conditions. The system 100 employs a “dual-zone” approach, in which pressure differentials between the source pressure and the desired tissue site pressure are monitored and then compared to one of two maximum differential pressures depending on whether a blockage is present. More specifically, if a desired tissue site pressure for the tissue site 102 has not been met, the source pressure at the reduced pressure source 104 will be increased and monitored by second sensing device 136. As the source pressure continues to be increased, the differential pressure between the source pressure and the desired tissue site pressure is determined. The differential pressure may be calculated by the processing unit 210 after receiving data from the second sensing device 136. As long as the differential pressure does not exceed the first maximum differential pressure, the reduced pressure treatment system 100 attempts to achieve the desired tissue site pressure at the tissue site 102. The first sensing device 132 continues to monitor the tissue site 102 to determine if the pressure at the tissue site 102 reaches the desired tissue site pressure.


The reduced pressure source is not allowed to continue increasing the source pressure indefinitely. Instead, the source pressure is limited based on the differential pressure between the source pressure and the desired tissue site pressure. In an initial “safe” or “green-zone” operation, the differential pressure will not be allowed to exceed a first maximum differential pressure. It has been found that a sudden clearing of a blockage can result in the source pressure being applied directly to the wound site. It is therefore necessary to limit the absolute source pressure to a safe differential above the desired tissue site pressure. Clinical practice has shown that about 50 mm Hg is a safe amount of differential pressure, and in one embodiment, the first maximum differential pressure is set to about 50 mm Hg. More specifically, for most tissue sites, an instantaneous change of about 50 mm Hg reduced pressure will not cause harm to the tissue site. Under many “blockage” situations, a 50 mm Hg or less differential pressure is sufficient to clear the blockage. However, in the event that a blockage is not cleared by this amount of differential pressure, the reduced pressure treatment system 100 will not allow a further increase in reduced pressure simply to clear the blockage. Instead, the processing unit 210 communicates an alarm condition indicating a blockage to the alarm 236 and continues to apply reduced pressure within the green-zone parameters (i.e. differential pressure not to exceed about 50 mm Hg).


If the differential pressure reaches the first maximum differential pressure (i.e. about 50 mm Hg) and the target pressure still exceeds the tissue site pressure, then a blockage test is performed. When a change in source pressure at the reduced pressure source 104 does not result in a directionally corresponding change in the tissue site pressure, a blockage is present between the tissue site 102 and the reduced pressure source 104. If a directionally corresponding change does occur as the tissue site 102 as indicated by first sensing device 132, then a blockage is not present.


If the blockage test determines that a blockage is not present, and the tissue site pressure does not yet equal the desired tissue site pressure, the source pressure may be safely increased as there is no risk of sudden onset of additional pressure to the tissue site. In this “red-zone” operation, the differential pressure will not be allowed to exceed a second maximum differential pressure. In one embodiment, the second maximum differential pressure is about 100 mm Hg. Red-zone operating parameters are provided for situations when the reduced pressure treatment system 100 has confirmed the absence of blockages between the reduced pressure source 104 and the tissue site 102. This mode of operation may be particularly useful in situations where excessive fluid head pressures at the tissue site cause the tissue site pressure to be much lower than the desired tissue site pressure despite repeated increases in the source pressure.


While it is preferred that the first maximum differential pressure be 50 mm Hg and the second maximum differential pressure be 100 mm Hg, these pressure values could vary depending on the particular tissue site being treated and individual medical considerations. Although the pressure protection system described above is a “dual-zone” system, it should be apparent that a multi-zone system having more than two pressure parameters may be employed to provide additional protections.


Referring to FIG. 3, a method 300 of treating a tissue site according to an embodiment of the present invention includes monitoring a source pressure at a reduced pressure source 304, monitoring a tissue site pressure at a tissue site 308, and determining a differential pressure between the source pressure and the desired tissue site pressure. If a blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a first maximum differential pressure at 316. If no blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a second maximum differential pressure at 320.


It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only a few of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof.

Claims
  • 1. A method of treating a tissue site comprising: applying a reduced pressure to a tissue site with a reduced pressure source;monitoring a source pressure at the reduced pressure source;determining a differential pressure between the source pressure and the desired tissue site pressure;if a blockage is present between the reduced pressure source and the tissue site, limiting the differential pressure to a first maximum differential pressure; andif no blockage is present between the reduced pressure source and the tissue site, limiting the differential pressure to a second maximum differential pressure, wherein the second maximum differential pressure is greater than the first maximum differential pressure.
  • 2. The method according to claim 1, wherein the first maximum differential pressure is about 50 mm Hg.
  • 3. The method according to claim 1, wherein the second maximum differential pressure is about 100 mm Hg.
  • 4. The method according to claim 1, wherein the step of determining the differential pressure further comprises monitoring the differential pressure.
  • 5. The method according to claim 1 further comprising: when a blockage is present, increasing the source pressure, within the limits of the first maximum differential pressure, to attempt to clear the blockage.
  • 6. The method according to claim 1 further comprising: when a blockage is present, increasing the source pressure, within the limits of the first maximum differential pressure, to attempt to clear the blockage; andif the blockage does not clear, generating an alarm to indicate that a blockage is present.
  • 7. The method according to claim 1 further comprising: changing the source pressure, within the limits of one of the first and second maximum differential pressures, to cause a pressure at the tissue site to reach a desired tissue site pressure.
  • 8. The method according to claim 1 further comprising: determining if a blockage is present by changing the source pressure and monitoring for a directionally corresponding change in a pressure at the tissue site; anddetermining that a blockage is present when no directionally corresponding change occurs in the pressure at the tissue site.
  • 9. The method according to claim 8, wherein changing the source pressure further comprises increasing the source pressure.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 11/903,165 filed Sep. 19, 2007 now U.S. Pat. No. 7,758,555, which claims the benefit of U.S. Provisional Application No. 60/849,138, filed Oct. 2, 2006, and U.S. Provisional Application No. 60/845,993, filed Sep. 19, 2006. All of the above-mentioned applications are hereby incorporated by reference.

US Referenced Citations (224)
Number Name Date Kind
1355846 Rannells Oct 1920 A
1885926 Lewis Jun 1931 A
2378849 Helleberg Jun 1945 A
2381821 Helleberg et al. Aug 1945 A
2547758 Keeling Apr 1951 A
2632443 Lesher Mar 1953 A
2682873 Evans et al. Jul 1954 A
2910763 Lauterbach Nov 1959 A
2969057 Simmons Jan 1961 A
3066672 Crosby, Jr. et al. Dec 1962 A
3367332 Groves Feb 1968 A
3376868 Mondiadis Apr 1968 A
3419006 King Dec 1968 A
3520300 Flower, Jr. Jul 1970 A
3568675 Harvey Mar 1971 A
3585861 Keng Jun 1971 A
3648692 Wheeler Mar 1972 A
3682180 McFarlane Aug 1972 A
3742952 Magers et al. Jul 1973 A
3744306 Krueger Jul 1973 A
3774611 Tussey et al. Nov 1973 A
3779243 Tussey et al. Dec 1973 A
3799702 Weishaar Mar 1974 A
3826254 Mellor Jul 1974 A
3892229 Taylor et al. Jul 1975 A
4080970 Miller Mar 1978 A
4091804 Hasty May 1978 A
4096853 Weigand Jun 1978 A
4139004 Gonzalez, Jr. Feb 1979 A
4141361 Snyder Feb 1979 A
4165748 Johnson Aug 1979 A
4184510 Murry et al. Jan 1980 A
4233969 Lock et al. Nov 1980 A
4245630 Lloyd et al. Jan 1981 A
4256109 Nichols Mar 1981 A
4261363 Russo Apr 1981 A
4275721 Olson Jun 1981 A
4284079 Adair Aug 1981 A
4297995 Golub Nov 1981 A
4333468 Geist Jun 1982 A
4373519 Errede et al. Feb 1983 A
4375217 Arkans Mar 1983 A
4382441 Svedman May 1983 A
4392853 Muto Jul 1983 A
4392858 George et al. Jul 1983 A
4419097 Rowland Dec 1983 A
4465485 Kashmer et al. Aug 1984 A
4475901 Kraegen et al. Oct 1984 A
4475909 Eisenberg Oct 1984 A
4480638 Schmid Nov 1984 A
4509959 McCombs Apr 1985 A
4525166 Leclerc Jun 1985 A
4525374 Vaillancourt Jun 1985 A
4529402 Weilbacher et al. Jul 1985 A
4534756 Nelson Aug 1985 A
4540412 Van Overloop Sep 1985 A
4543100 Brodsky Sep 1985 A
4548202 Duncan Oct 1985 A
4551139 Plaas et al. Nov 1985 A
4553431 Nicolai Nov 1985 A
4569348 Hasslinger Feb 1986 A
4569674 Phillips et al. Feb 1986 A
4600015 Evans et al. Jul 1986 A
4605399 Weston et al. Aug 1986 A
4608041 Nielsen Aug 1986 A
4640688 Hauser Feb 1987 A
4650462 DeSatnick et al. Mar 1987 A
4655754 Richmond et al. Apr 1987 A
4664652 Weilbacher May 1987 A
4664662 Webster May 1987 A
4698060 D'Antonio et al. Oct 1987 A
4710165 McNeil et al. Dec 1987 A
4713052 Beck et al. Dec 1987 A
4722332 Saggers Feb 1988 A
4733659 Edenbaum et al. Mar 1988 A
4743232 Kruger May 1988 A
4758220 Sundblom et al. Jul 1988 A
4787888 Fox Nov 1988 A
4798583 Beck et al. Jan 1989 A
4826494 Richmond et al. May 1989 A
4838883 Matsuura Jun 1989 A
4840187 Brazier Jun 1989 A
4863449 Therriault et al. Sep 1989 A
4872450 Austad Oct 1989 A
4878901 Sachse Nov 1989 A
4897081 Poirier et al. Jan 1990 A
4906233 Moriuchi et al. Mar 1990 A
4906240 Reed et al. Mar 1990 A
4917112 Kalt Apr 1990 A
4919654 Kalt et al. Apr 1990 A
4941882 Ward et al. Jul 1990 A
4953565 Tachibana et al. Sep 1990 A
4969880 Zamierowski Nov 1990 A
4981474 Bopp et al. Jan 1991 A
4985019 Michelson Jan 1991 A
5000741 Kalt Mar 1991 A
5001924 Walter et al. Mar 1991 A
5037397 Kalt et al. Aug 1991 A
5055198 Shettigar Oct 1991 A
5086170 Luheshi et al. Feb 1992 A
5092858 Benson et al. Mar 1992 A
5100396 Zamierowski Mar 1992 A
5106629 Cartmell et al. Apr 1992 A
5112323 Winkler et al. May 1992 A
5134994 Say Aug 1992 A
5149331 Ferdman et al. Sep 1992 A
5160315 Heinecke et al. Nov 1992 A
5167613 Karami et al. Dec 1992 A
5176663 Svedman et al. Jan 1993 A
5195995 Walker Mar 1993 A
5215522 Page et al. Jun 1993 A
5232453 Plass et al. Aug 1993 A
5261893 Zamierowski Nov 1993 A
5278100 Doan et al. Jan 1994 A
5279550 Habib et al. Jan 1994 A
5298015 Komatsuzaki et al. Mar 1994 A
5342329 Croquevielle Aug 1994 A
5342376 Ruff Aug 1994 A
5344415 DeBusk et al. Sep 1994 A
5358494 Svedman Oct 1994 A
5380294 Persson Jan 1995 A
5423737 Cartmell et al. Jun 1995 A
5429593 Matory Jul 1995 A
5435009 Schild et al. Jul 1995 A
5437622 Carion Aug 1995 A
5437651 Todd et al. Aug 1995 A
5489262 Cartmell et al. Feb 1996 A
5497788 Inman et al. Mar 1996 A
5520629 Heinecke et al. May 1996 A
5526683 Maggio Jun 1996 A
5527274 Zakko Jun 1996 A
5527293 Zamierowski Jun 1996 A
5538502 Johnstone Jul 1996 A
5549584 Gross Aug 1996 A
5556375 Ewall Sep 1996 A
5562615 Nassif Oct 1996 A
5607388 Ewall Mar 1997 A
5628230 Flam May 1997 A
5636643 Argenta et al. Jun 1997 A
5645081 Argenta et al. Jul 1997 A
5645539 Solomon et al. Jul 1997 A
5653244 Shaw Aug 1997 A
5690815 Krasnoff et al. Nov 1997 A
5808181 Wamsiedler et al. Sep 1998 A
5810765 Oda Sep 1998 A
5895869 Von Behrens et al. Apr 1999 A
5907093 Lehmann May 1999 A
5950238 Klein Sep 1999 A
6071267 Zamierowski Jun 2000 A
6086450 Mankovitz Jul 2000 A
6109267 Shaw et al. Aug 2000 A
6135116 Vogel et al. Oct 2000 A
6142982 Hunt et al. Nov 2000 A
6162960 Klein Dec 2000 A
6174306 Fleischmann Jan 2001 B1
6241747 Ruff Jun 2001 B1
6287316 Agarwal et al. Sep 2001 B1
6302653 Bryant et al. Oct 2001 B1
6345623 Heaton et al. Feb 2002 B1
6361397 Mankovitz et al. Mar 2002 B1
RE37651 Wallsten et al. Apr 2002 E
6402714 Kraft-Kivikoski Jun 2002 B1
6420622 Johnston et al. Jul 2002 B1
6440093 McEwen et al. Aug 2002 B1
6488643 Tumey et al. Dec 2002 B1
6493568 Bell et al. Dec 2002 B1
6537495 Cambron et al. Mar 2003 B1
6553998 Heaton et al. Apr 2003 B2
6585675 O'Mahoney et al. Jul 2003 B1
6626891 Ohmstede Sep 2003 B2
6648862 Watson Nov 2003 B2
6685681 Lockwood et al. Feb 2004 B2
6752794 Lockwood et al. Jun 2004 B2
6764462 Risk, Jr. et al. Jul 2004 B2
6767188 Vrane et al. Jul 2004 B2
6814079 Heaton et al. Nov 2004 B2
6824533 Risk et al. Nov 2004 B2
6855135 Lockwood et al. Feb 2005 B2
6867342 Johnston et al. Mar 2005 B2
D503509 Bell et al. Apr 2005 S
6932786 Giacomelli et al. Aug 2005 B2
6979324 Bybordi et al. Dec 2005 B2
7070584 Johnston et al. Jul 2006 B2
7090647 Mimura et al. Aug 2006 B2
7135007 Scott et al. Nov 2006 B2
7144294 Bell et al. Dec 2006 B2
7195624 Lockwood et al. Mar 2007 B2
7201263 Osada et al. Apr 2007 B2
7252014 Mayer et al. Aug 2007 B1
7438705 Karpowicz et al. Oct 2008 B2
7670323 Hunt et al. Mar 2010 B2
7758555 Kelch et al. Jul 2010 B2
7927319 Lawhorn Apr 2011 B2
20020065494 Lockwood et al. May 2002 A1
20020077661 Saadat Jun 2002 A1
20020115951 Norstrem et al. Aug 2002 A1
20020120185 Johnson Aug 2002 A1
20020143286 Tumey Oct 2002 A1
20030032915 Saul Feb 2003 A1
20030040687 Boynton et al. Feb 2003 A1
20040064132 Boehringer et al. Apr 2004 A1
20040073151 Weston Apr 2004 A1
20050070858 Lockwood et al. Mar 2005 A1
20050137539 Biggie et al. Jun 2005 A1
20050148913 Weston Jul 2005 A1
20050197647 Doliver et al. Sep 2005 A1
20050261642 Weston Nov 2005 A1
20050261643 Bybordi et al. Nov 2005 A1
20060025727 Boehringer et al. Feb 2006 A1
20060122558 Sherman et al. Jun 2006 A1
20060173253 Ganapathy et al. Aug 2006 A1
20060189887 Hassler, Jr. et al. Aug 2006 A1
20060229531 Goldberger et al. Oct 2006 A1
20070032762 Vogel Feb 2007 A1
20070032763 Vogel Feb 2007 A1
20070055209 Patel et al. Mar 2007 A1
20070078444 Larsson Apr 2007 A1
20070118096 Smith et al. May 2007 A1
20070167927 Hunt et al. Jul 2007 A1
20070265586 Joshi et al. Nov 2007 A1
20080071235 Locke et al. Mar 2008 A1
20080125698 Gerg et al. May 2008 A1
20090099498 Demers Apr 2009 A1
20100022934 Hogard Jan 2010 A1
Foreign Referenced Citations (37)
Number Date Country
550575 Aug 1982 AU
745271 Apr 1999 AU
755496 Feb 2002 AU
2005436 Jun 1990 CA
2805782 Aug 2006 CN
26 40 413 Mar 1978 DE
43 06 478 Sep 1994 DE
295 04 378 Oct 1995 DE
0100148 Feb 1984 EP
0117632 Sep 1984 EP
0161865 Nov 1985 EP
0358302 Mar 1990 EP
1018967 Aug 2004 EP
692578 Jun 1953 GB
2 195 255 Apr 1988 GB
2 197 789 Jun 1988 GB
2 220 357 Jan 1990 GB
2 235 877 Mar 1991 GB
2 333 965 Aug 1999 GB
2 329 127 Aug 2000 GB
4129536 Apr 1992 JP
71559 Apr 2002 SG
WO 8002182 Oct 1980 WO
WO 8704626 Aug 1987 WO
WO 9010424 Sep 1990 WO
WO 9309727 May 1993 WO
WO 9420041 Sep 1994 WO
WO 9605873 Feb 1996 WO
WO 9718007 May 1997 WO
WO 9825122 Jun 1998 WO
WO 9913793 Mar 1999 WO
WO 0021586 Apr 2000 WO
WO 03101508 Dec 2003 WO
WO 2007133618 Nov 2007 WO
WO 2008036360 Mar 2008 WO
WO 2009019496 Feb 2009 WO
WO 2009071926 Jun 2009 WO
Related Publications (1)
Number Date Country
20100268179 A1 Oct 2010 US
Provisional Applications (2)
Number Date Country
60849138 Oct 2006 US
60845993 Sep 2006 US
Divisions (1)
Number Date Country
Parent 11903165 Sep 2007 US
Child 12824582 US